Form for concrete structures.



W. P. CUNNINGHAM.

FORM FOR CONCRETE STRUCTURES.

APPLICATION FILED MAY3.1915.

UNITED STATES PATENT OFFICE.

WILLIAM P. CUNNINGHAM, O WAUKEGAN, ILLINOIS, ASSIGNOR TO AMERICAN METALFORM COMPANY, 0F CHICAGO, ILLINOIS, A CORPORATION 0F ILLINOIS.

FORM FOR CONCRETE STRUCTURES.

To all 'whom y1' t may conce/'11.

Be it known that I, WYiLLiAM I. CUN- NINGHAM, a citizen of lthe UnitedStates, and a resident of lVaukegan, county of Lake, and State ofIllinois, have invented certain new and "useful Improvements in Formsfor Concrete Structures,vof which the following is declared to be afull, clear, and exact description.

This invention relates to forms for concrete structures, such ascolumns, posts, conduits, pipes and other solid'or hollow cone cretestructures of like formation, and its principal object is to provide asheet metal tubular form or mold comprising sections capable of beingbuilt up into a form of any desirable length., and having novel meansfor joining the side edges of the sections to make tight joints'thereat, and for holding said edges securely together; also to Y providemeans for preventing outward bulging of the form from internal pressure.

Other objects and advantages will appear in the course of thisspecificationand with all of said objects and advantages in view, thisinvention consists in the several novel features hereinafter fully setforth and claimed.

The invention is clearly illustrated in the accompanying drawing, inwhich Figure 1 is a side elevation partly broken out, showing a simpleembodiment of the present invention; Fig. 2 is a horizontal sectiontaken on line Q-Q of Fig. l; Fig. 3 is an end view of one sectionshowing certain retaining means therefor; and Fig. 4 is a detail,horizontal section taken on the line 4 4 of Fig. l.

In carrying out my invention, I employ one or more sections, 10, 11, oftubular formation, preferably cylindrical, although not necessarily so,each section being constructed of one or more metal sheets or plates,12, of the desired shape to form the complete section when the edges ofsaid sheets are se cured together. In the form of the inventionillustrated herein, three arcuate metal sheets or plates are employed,and by increasing or decreasing the width of any sheet or plate thediameter of the form may be varied within certain limits to formcylindrical concrete structures of various diameters.

At the meeting edges kof the sheets or plates are joints, 13, ofnovelconstruction. As shown, said joints are formed by bend- PatentedFeb. 1, 1916.

Application led May 3, 1915. Serial No. 25,419.

ing the plates outward, in a radial direction (as at 11) and thenbending the edge portions thereof into angle-shaped, or substantiallyV-shaped portions, as clearly seen in Fig. 2, at 15, the angle portionof one nesting into or interlocking with that of the other. Means areprovided for temporarily securing together said bent up edge portionsand a simple clamping means may comprise the ordinary and well-knownclamp screw seen at 16, comprising a yoke, 17, and a screw, 1S, threadedin one end thereof. A plurality of clamp screws are employed along eachjoint for clamping the radial webs, 14, together between the screws, 17,and opposing end of the yoke, 18. The bent up ends, besides serving asjoints for the meeting edges of the sheets or plates, act asstrengthening ribs for the form and resist outward buckling of theplates at the joints. It is to be observed that this particular form ofjoint maintains a flush internal face at the joint, because the V orangle-shaped portions hold the sheets against movement relative to eachother in a radial direction by reason of the fact that one 'V or angleshaped portion of one sheet nests into and interlocks with the other.

For the purpose of positively holding the form in shape While theconcrete is being poured thereinto and before it sets, I provideretainers, 19, preferably in the form of sectional rings, the innerfaces of which fit against the outer face of the form and aretemporarily secured thereon' by fastening means, here shown ascomprising flexible tie wires or rods, 20, Wrapped around the rings andhaving their endsv secured together, as, for instance, by twisting themtogether. The ends of the sections of each ring are shaped to conformgenerally to the shape of the joints, although this is not essential tothe invention, broadly speaking. Said retaining rings are preferablyplaced at the endsof the form and also intermediate the ends.

The form may be made in suitable lengths and may comprise a singlesection, but Where it. is necessary to erect a form of greater lengththan one section, then two or more telescoping sections are used. Theproper length of form may then be had by adjusting thesections'lengthwise of each other. In cases where two or more sectionsare used, the joints at the overlapping portions nest into each other asshown in Fig. 4, and hold the several, adjacent sheets or plates inproper position.

Among some ofthe particular advantages of this form, are its simplicityof construction; the elimination of bolt holes and bolts at the jointsbetween the sheets; and its rigidity and ease with which it is erectedand taken down.

I 'realize 'that various alterations and modications of this device arepossible without departing from the spirit of my invention, and Idesire, therefore, not to limit myself to the exact form of theinvention shown and described, but intend in the following claims topoint out all of the invention disclosed herein.

I claim as new and desire to secure by Letters Patent:

l. A form for concrete structures, comprising a tubular wall having ajoint along its side comprising outwardly bent edge portions, havingradial abutting portions terminating in an outward bearing surface andan inward bearing surface, the one interlocking with the other, andclamping means disposed along the radial portions of said joint.

2. A form for concrete structures comprising a tubular wall having ajoint along its side and comprising outwardly and radially bent portionsterminating in V- shaped, marginal portions, theone nesting 4. A formfor concretestructures coml prising a plurality of metal sheets arrangedin tubular form, their adjacent edges having radial abutting portionsterminating in V-shaped, interlocking portions, clamp members disposed'along the radial portions of said edge portions for clamping them t0-gether, a sectional, retaining ring'disposed around and litting againstsaid sheets, and means for securing said sectional ring in place.y

5. A form for concreteV structures' comprising a plurality oftelescoping sections, each formed of metal, arcuate sheets arranged intubular form,rthe adjacent'edge portions of said sheets having abuttingradial portions which are V-shaped in cross section, and nestedtogether, and clamp members disposed along the radial portions of saidedge portions, and clamped thereon.

IVILLIAM P. CUNNINGHAM.

